The haemolysis of blood samples is a source of error in the electrolytic and enzymatic determination in clinical biochemistry. This circumstance seems dependent on the material used for the venepuncture. In this study we compared three kinds of material in 350 patients who were sampled in the emergency department. This randomized study compared the haemolysis of blood samples collected with stainless steel needles and short catheters, either Teflon FEP (Cathlon Critikon) or polyurethane Vialon (Insyte Becton-Dickinson)...

Post-infusion phlebitis remains one of the most frequent causes of hospital morbidity with an incidence varying between 13 and 39 per cent (1-4). A recent study indicated that a silicone elastomer cannula (Visis) had desirable properties (5). We have carried out a prospective trial comparing the value of such a cannula with a Teflon cannula (Cathlon) already in routine use.

The interior and exterior surfaces of four plastic, 18-gauge intravenous catheters (Abbocath-T, angiocath, Cathlon IV and Quik-Cath) were examined to identify physical characteristics that could possibly contribute to clinical thrombogenic activity. For each brand, the surface characteristics of one unused catheter (control) and a catheter placed in the left-cephalic vein of an orthopedic surgery patient for 48 hours were compared by scanning electron microscopy. All catheters had surface imperfections. Fibrinous material was found adhering to all used catheters even though exposure of the interior surfaces to blood components was minimal...